14.5.6 Errors That May Occur When Using BDB Tables

If the following error occurs when you start
mysqld after upgrading, it means that the
current version of BDB doesn't support the
old log file format:

bdb: Ignoring log file: .../log.NNNNNNNNNN:
unsupported log version #

In this case, you must delete all BDB logs
from your data directory (the files that have names of the
form
log.NNNNNNNNNN)
and restart mysqld. We also recommend that
you then use mysqldump --opt to dump your
BDB tables, drop the tables, and restore
them from the dump file.

If autocommit mode is disabled and you drop a
BDB table that is referenced in another
transaction, you may get error messages of the following form
in your MySQL error log: